This invention relates to sustained-holding-strength fasteners and devices and methods for delivering the fasteners into tissues.
In recent years, much attention has been given to controlling surgical costs. One of the cost-effective approaches is to accelerate the speed of recovery and shorten post-surgical hospital stays. In addition to lowering costs, for the comfort and safety of patients, minimally invasive or endoscopic surgeries are becoming more and more popular. The term xe2x80x9cendoscopicxe2x80x9d used in this invention encompasses arthroscopic, laparoscopic, hysteroscopic and other instrument viewing procedures. Endoscopy is a surgical procedure, which allows surgeons to manipulate instruments to view and operate the surgical sites through small incisions in the bodies of patients.
In order to minimize both the patients"" trauma and potential damage to nerves, blood vessels and other tissues, it is clearly desirable to minimize the size and number of holes puncturing the patients. Take meniscal repair in the knee for example, the current arthroscopic procedure requires one hole for the arthroscope, one hole for a needle to deliver a suture and another hole for a suture-retrieving instrument to complete one suture stitch (Arthroscopic Surgery by L. Johnson, M.D.; Knee Surgery by F. Fu, MD, et al.; Traumatic Disorders of the Knee by J. Siliski, MD; and Knee Surgery Current Practice by P. Aichroth, FRCS et al.). A minimum of three holes is made for the arthroscopic repair. In some cases, surgeons also require a distractor, an external fixation device that is screwed in through skin to the bones, separating the femur from the tibia. This expands the knee joint and makes room to manipulate both the suture and the suture-retrieving instrument. Due to the tightness of joint space, often a needle or instrument can accidentally scrape and damage the smooth surface of the joint cartilage, which given time, can potentially lead to osteoarthritis years after the surgery.
Recently, instead of delivering, manipulating and retrieving a suture, often in a very tight surgical site, delivery of tacks with barbs (U.S. Pat. No. 5,702,462 to Oberlander, 1997; U.S. Pat. No. 5,398,861 to Green, 1995; U.S. Pat. No. 5,059,206 to Winters, 1991; U.S. Pat. No. 4,895,148 to Bays et. al., 1990; U.S. Pat. No. 4,884,572 to Bays et. al., 1989), staples (U.S. Pat. No. 5,643,319 to Green et. al., 1997) and fasteners (U.S. Pat. No. 5,843,084 to Hart et. al., 1998; U.S. Pat. No. 5,374,268 to Sander, 1994; U.S. Pat. No. 5,154,189 to Oberlander et. al., 1992) through a small opening to hold tom tissue, such as the meniscus, in place have been implemented. Unfortunately, very few, if any, of these tacks, staples and fasteners have the holding strength to meet the standard set by sutures.
During the insertion of these devices into tissues, the barbs carve their way into their final holding position. Unavoidably, the carving damages the tissue, and thus weakens it thereby decreasing the holding strength of the freshly inserted devices. As tension is applied to the fastened tissue, it is not surprising that the barbs can lose their grip, slip and creep along the carved paths created during insertion, leaving gaps in the supposed closure sites. The creeping problem of fastening devices is particularly evident in slow healing tissues, such as menisci, and also in tissues providing high tensile strength, such as ligaments and tendons. Since gaps are present, the torn tissue does not reattach and heal, even with the passage of time.
Non-biodegradable fasteners often have the problem of device migration, which can be devastating, especially into nerves, joints or vessels, after numerous cycles of tissue remodeling.
In summary, currently most of the tacks or fasteners have one or more of the following drawbacks: (1) weak holding strength, (2) creeping and leaving gaps in the repair site, and (3) potential migration into sensitive tissues.
Numerous staples (U.S. Pat. No. 5,829,662 to Allen et. al., 1998; U.S. Pat. No. 5,826,777 to Green et. al., 1998; U.S. Pat. No. 5,817,109 to McGarry et. al., 1998; U.S. Pat. No. 5,794,834 to Hamblin et. al., 1998; U.S. Pat. No. 5,715,987 to Kelley et. al., 1998; U.S. Pat. No. 5,662,662 to Bishop et. al., 1997; U.S. Pat. No. 5,413,584 to Schulze, 1995; U.S. Pat. No. 5,333,772 to Rothfuss et. al., 1994; U.S. Pat. No. 5,304,204 to Bregen, 1994; U.S. Pat. No. 5,257,713 to Green et. al., 1993; U.S. Pat. No. 5,089,009 to Green, 1992; U.S. Pat. No. 5,002,563 to Pyka et. al., 1991; U.S. Pat. No. 4,944,295 to Gwathmey, 1990; U.S. Pat. No. 4,671,279 to Hill, 1987; U.S. Pat. No. 4,485,816 to Krumme, 1984; U.S. Pat. No. 4,396,139 to Hall et. al., 1983) are designed and used for shallow penetration of the staple, mostly to fasten superficial tissues only.
The term xe2x80x9cfastenerxe2x80x9d used in this invention encompasses tacks, staples, screws, clamps and other tissue holding devices.
Meniscal damage often accompanies a torn anterior cruciate ligament, ACL, which stabilizes the femoro-tibial joint. Due to the linear orientation of the collagen fibers and the enormous tensile strength required of the ACL, it is often difficult to reattach the ligament by suture. When tensile forces are applied, the suture cuts and tears the collagen fibers along their linear orientation. Therefore, the traditional ACL repair is to abandon the torn ACL altogether. To replace the ACL, a strip of patellar ligament is harvested from the patient. Two bone holes are drilled, one through the tibia and another through the femur. The strip of patellar ligament is threaded through the bone holes. Both ends of the patellar ligaments are then stapled to the anterior surfaces of femur and tibia through incisions of skin covering each bone. The traditional ACL repair is an invasive surgery. To minimize the degree of invasiveness and eliminate opening the skin for ligament stapling, bone fixation devices (U.S. Pat. No. 5,147,362 to Goble, 1992, U.S. Pat. No. 5,129,902 to Goble, et. al. 1992) are designed to grip the ligament replacement inside the drilled hole of the bone.
Low-back pain is one of the most prevalent and debilitating ailments of mankind. For many people, no position can ease the pain or numbness, not even bed rest. It is often the reason for decreased productivity due to loss of work hours, addiction to pain-killing drugs, emotional distress, prolonged hospital stays, loss of independent living, unplanned early retirements, and even financial ruin. Some may experience it occasionally; others suffer from it for years. One common reason for this chronic pain is the bulging or herniation of an intervertebral disc, which can cause sciatica.
The traditional surgical treatment for a bulging or herniated disc is a series of tissue removing, filling and supporting procedures: (1) laminectomy, removal of the lamina from the vertebra which covers part of the herniated disc, (2) discectomy, removal of the disc, (3) bone harvesting usually from the patient""s iliac crest, (4) bone cement filling of the donor site, (5) donor bone packing into the vacant disc space, (6) adjacent vertebra supporting with rods, connectors, wire and screws, and finally, (7) surgical site closing.
After a discectomy, numerous postoperative complications can occur. The major ones are lumbar scarring and vertebral instability. The scar tissue extends and encroaches upon the laminectomy site and intervertebral foramen, then once again, pain returns, which leads to more surgery. In fact, re-operation is very common. Unfortunately, the success rate of re-operation is often less, in some cases, far less than the first. More operations lead to more scarring and more pain. Current emphasis to the patients is to avoid surgical procedures, unless the pain and inconveniences are absolutely unbearable.
Even for the fortunate patients with long term success following discectomies twenty years ago, their isokinetic test results clearly indicate weaknesses compared to populations without discectomies.
There was and still is increasing interest in less invasive surgical techniques on the spine to reduce both trauma and cost. The major objectives of surgery on bulging or herniated lumbar discs are (1) decompression of the involved nerve root or roots, and (2) preservation of bony spine, joints and ligaments.
Chymopapain is an enzyme used to digest away the nucleus pulposus, the gel-like substance in the central portion of the disc, which then creates space for the bulging part of the disc to pull back from the encroached nerve root. The needle for injecting the chymopapain is accurately guided to the mid-portion of the disc by a stereotaxic device. The overall success rate is documented as high as 76%. However, some patients are allergic to the treatment and die from anaphylaxis. Some others suffer from serious neuralgic complications, including paraplegia, paresis, cerebral hemorrhage and transverse myelitis (Lumbar Spine Surgery, Arthur White, M.D., Richard Rothman, M.D., Charles Ray, M.D.).
Percutaneous nuclectomy is an alternative method for removing nucleus pulposus without the allergic reaction of chymopapain. Similar to chymopapain injection, a needle followed by a tube-like instrument is guided and confirmed by anteroposterior and lateral fluoroscopy. The nucleus pulposus is then removed by mechanical means or by vacuum. As a result, a void is created within the disc and the bulging decreases, like the air being released from a worn out tire, with the hope that the bulging portion of the disc will recede and no longer encroach upon the adjacent nerve root. This type of procedure is often referred to as a decompression procedure. Unfortunately, there is no guarantee that the decompression will reduce enough bulging or herniation to alleviate pain.
Regarding immediate postoperative complications, percutaneous nuclectomy appears to be safer than either discectomy or chymopapain. There is little epidural scarring, allergic reactions, or serious neurologic complications. However, the case history using this percutaneous procedure has been relatively short, and the long-term outcome is not yet known.
The function of the nucleus pulposus, with its high water absorbing composition of mucoprotein and mucopolysaccharides, is to sustain prolonged compression during the day, and to resiliently re-inflate and re-establish disc height during the night. The pulposus is retained and surrounded by layers of cartilaginous annulus. Together the pulposus and the annulus behave as a resilient and cushioning water balloon. In the erect position, the weight of the body constantly compresses upon a stack of these water balloons alternating between a series of vertebrae. During constant compression, the pulposus in each disc also behaves as a water reservoir, which is slowly and constantly being squeezed and drained of its water content through the end plates connected to the vertebrae. As a result, the disc height decreases throughout the day. During bed rest, the weight of the body no longer compresses the disc. Due to the water absorbing nature of the nucleus pulposus, the flow of water is now reversed from the vascular vertebrae back into the mucoprotein and polysaccharides. As a result, the disc height is re-established, ready to provide support for another day (Clinical Biomechanics of the Spine, 2nd ed., Augustus White, M.D., Manohar Panjabi, Ph.D.).
Aging, poor posture and trauma from heavy lifting contribute to an increase in annular fibrotic elements. The disc dries out and greatly loses height between vertebrae. Bone around the dried out disc grows a rim and spurs, which protrude and invade the intervertebral foramina and infringe upon nearby nerves. This continual, painful bone growth process causes stenosis.
After the removal of the water absorbing and water retaining pulposus by the percutaneous procedure, the remaining disc is no longer assembled as a water balloon; the annulus becomes more like a flat tire with minimal resiliency. In the erect position, compression forces are solely exerted upon the cartilaginous annulus alone. During bed rest, little if any water is re-absorbed by the annulus. With the passage of time, it is conceivable that the annulus will flatten out and the disc height will permanently decrease. As the vertebrae above and below the disc come closer together with less and less disc space, the growth of bone spurs and rim appear. The stenotic process has just begun. The pain returns. Unfortunately, unlike the previous irritation by the bulging disc, this time the sensation of pain comes from nerve compression by solid bones. Surgical procedures can be very involved, and the potential complications and scarring can be enormous.
In short, percutaneous nuclectomy may be a quick fix for decompressing a bulging or herniated disc without allergic reaction. However, within a not so distant future, there may be a much more complicated and painful ailment waiting.
Recently, several devices (U.S. Pat. No. 5,800,550 to Sertich, 1998; U.S. Pat. No. 5,683,394 to Rinner, 1997; U.S. Pat. No. 5,423,817 to Lin, 1995; U.S. Pat. No. 5,026,373 to Ray et. al., 1991) were designed to fortify the disc space between vertebrae. These types of devices are frequently referred to as spinal cages. Before inserting the device into the disc, the affected disc with portions of vertebral bone above and below the disc are cored out. Usually two holes are cored, one on each side of the disc, to insert two spinal cages. Donor bone or bone-growth promoting substances are packed into the porous cages. As the vertebrae heal from the coring, new bone grows into and permanently secures the porous cages. The purpose of using spinal cages is to replace the disc and keep the vertebrae apart. However, these vertebrae are permanently fused to each other, without resilient cushion, rotation or flexibility.
An improved version of a metallic spinal fusion implant (U.S. Pat. No. 5,782,832 to Larsen and Shikhman, 1998) tries to provide both rotational and cushioning capability. This invention resembles a disc prosthesis following a complete discectomy. Therefore, at least all the complications and postsurgical problems associated with a discectomy apply when this device is used.
In many accidents or sports related injuries, tendons or ligaments rupture from bones. Some very strong bone anchors (U.S. Pat. No. 5,851,219 to Goble et. al., 1998; and U.S. Pat. No. 5,478,353 to Yoon, 1995) have been invented and used with sutures to reattach ruptured tissues. Attached to a suture, the anchor is inserted into a pre-drilled bone hole. The suture usually comes with a needle for sewing and attaching the torn tissue back to bone. The manipulation of suture and attachment of tissue requires not only skill and time from the surgeon, it also requires operative space in the body of the patient. To obtain the space for suture manipulation, a sizable incision or multiple incisions are often required to complete a repair.
Urinary or fecal incontinence is far more common than expected. A recent finding from a large telephone survey of over 2500 households with nearly 7000 individuals reveals that for anal incontinence alone, 2.2% of the general population has the problem. Incontinent problems, urinary and fecal alike, can and usually do alter the lifestyles of the suffering individuals, resulting in (1) social withdrawal, (2) decreased exercise, (3) altered clothing choices, (4) minimized travel, (5) avoidance of sexual relationships and/or (6) spending over $2,000 per year for disposable or washable pads, laundry, medications and skin care products (Urology Times, February 1996).
One of the major causes of fecal incontinence in women is vaginal delivery of babies. In the United States, between 4% and 6% of women who have vaginal deliveries suffer from fecal incontinence. Fecal incontinence often coexists with urinary incontinence and may signify pudenda nerve damage. Many of these patients were found to have a weak anal sphincter, as evidenced by low anal squeeze pressures. Disruption of the anal sphincters has been attributed to episiotomies, perineal lacerations and forceps extractions.
There are several other common causes of fecal incontinence. With age, the internal anal sphincter thickens with fibrotic tissue and loses the viscoelastic properties, which are required for closure. Also, trauma can tear and permanently scar the sphincter, resulting in a continual leakage problem.
Open surgery is often performed to tighten the sphincter muscle with a suture or to replace the sphincter with an artificial elastic band. Like all other open surgeries, the incision is large; recovery is lengthy; and the medical cost is high. Furthermore, unlike most other surgical sites, which can recover undisturbed, fecal excretion is unavoidable. Sphincter repairs often encounter infection, hemorrhage, hematoma and/or other complications.
For stress urinary incontinence, there are more successful surgical procedures and effective devices to treat women than the ones used to treat men. For example, collagen, a paste-like formulation, is used to inject and bulk up the sphincter wall. Alleviating incontinence after one collagen treatment is rare for women, and it often requires five to six treatments to achieve a satisfactory level for men. Even for the individuals who endure the injections, collagen often tends to lose its bulk within a few months. Similarly, fat injections have been tried and are reabsorbed by the patient within months. Teflon-based non-absorbable materials were used, but the materials migrate away and lose their bulk and effectiveness (Urology Times, December 1997).
A disposable, inflatable urethral occlusive device has been designed for women (Urology Times, March 1995), and a penile clip for men (U.S. Pat. No. 4,942,886 to Timmons, 1990). These devices are very unnatural and uncomfortable.
For women, there are several common and effective surgical procedures for repairing intrinsic sphincter deficiencies. A vaginal sling provides an elastic support to the sphincter unit by compressing the vaginal wall (Urology Times, July 1994). However, this surgical procedure can alter the patient""s sexual function. Bladder neck closure is infrequently performed and is irreversible. Potential complications of these surgical procedures include prolonged urinary retention, suprapubic pain, cellulitis, entrapment of genitofemoral or ilioinguinal nerve, vaginitis and/or suture infection (Glenn""s Urologic Surgery, fifth edition, editor Sam Graham Jr., M.D., 1998).
Carpal tunnel syndrome is a painful and debilitating ailment of the hand and wrist widely believed to be caused by prolonged repetitive hand activities. Predisposing factors include congenital narrowing of the carpal tunnel, trauma to carpal bones, acute infection, endocrine imbalance, contraceptive medication or rheumatoid disease. The weakness, numbness, pain and clumsiness of carpal tunnel syndrome are mainly attributable to swelling or thickening of the tenosynovium and compression of the median nerve under the flexor retinaculum. Prolonged compression can lead to narrowing of the nerve with intraneural fibrosis, resulting in irreversible loss of function.
The conservative treatment using splintage to restrict hand and wrist activity is helpful for about 70% of the patients. With the restricted hand and wrist, many patients can no longer perform their jobs. Corticosteroid injections are often effectively used to reduce the inflammatory edema around the median nerve, but corticosteroids are not a long-term solution.
The most common surgical procedure for relieving compression of the median nerve is carpal tunnel decompression, which enlarges the carpal tunnel by severing the entire width of the flexor retinaculum. After the procedure, the hand is restricted for a month. Weakness and pain are felt for some time. Even with the surgical procedure, about 10% of the patients experience no improvement or even more pain (Carpal Tunnel Syndrome, Bruce Conolly, FRCS, 1984).
Carpal tunnel decompression is often associated with one or more surgical complications. Early postoperative complications include hematoma, edema and infection. Subsequent common complications are weakness of grip, stiffness of fingers, wrist and shoulder, adhesions of flexor tendons and/or pain from scar tissue entrapment of the cutaneous nerve (Hand Rehabilitation, 2nd Ed., Gaylord Clark, M.D, et. al.).
Tumors, uncontrolled and rapidly growing tissues, demand extra nutrients by tapping adjacent arteries to feed and multiply the cancer cells. One of the most effective treatments of tumors is surgical removal. Often, the tumor is too large or too close to delicate tissues, such as nerves. To reduce the size of the tumor prior to surgical removal, radiation and chemotherapy are commonly used. However, both of these supporting techniques are invasive to the patients, who may face a long battle with cancer. As a less invasive approach, drugs are currently under investigation for reducing the new arterial growth feeding the tumor. These drugs are not likely to affect the existing arteries already feeding the tumor.
In keeping with the foregoing discussion, the present invention takes the form of a resilient fastener, which can be guided, delivered and deployed into tissue to provide a strong holding strength with sustained gripping forces. The fastener may be deployed using a fastener delivery device according to the methods described herein or by other devices and methods.
The fastener can reattach torn tissue, anchor a suture, fortify tissue, fasten protruded tissue, elastically close a sphincter, partially close a canal, permanently close a vessel or beneficially alter the shape of tissue.
Following the deployment of the first fastener, additional fasteners can also be deployed through the same puncture site providing additional strength, especially if different holding directions and positions are utilized. The additional fasteners may be deployed without completely withdrawing the delivery device from the puncture site.
The major components of the fastener delivery device are two tubes; one tube fits inside the bore of the other. For tissue penetration purposes, the outer tube can be sharpened at the distal opening and will be referred to as a needle. The main function of the inner tube is to hold the fasteners, and will be referred to as a cartridge. Both needle and cartridge have slits on the walls opened to their distal openings. As the needle and cartridge rotate against each other, the slits can line up, overlapping each other. When the slits overlap, they are in-phase. When the slits do not overlap each other, they are out-of-phase. For the cartridge, the slit is preferred to be opened length-wise from the distal opening all the way to or near the proximal opening.
The third component of the fastener delivery device is the fastener itself. The width of the fastener is no wider than the slits in the cartridge and in the needle. At least a portion of the fastener is made with a spring-like, flexible, resilient, elastic, super-elastic or shape memory material, and at least a portion of the fastener consists of tissue gripping elements. The fastener is made with curvature and gripping elements. Due to the spring-like or shape memory portion of the fastener, it can be elastically straightened either by mechanical constraint or temperature and is capable of resiliently curving back to or near the original shape when mechanical constraint is lifted or a transformation temperature is met. For simplicity, the resiliency of the fastener described in the text of this invention will concentrate on the mechanical constraint. However, it is understood that temperature may also be used.
The elastic fastener is or fasteners are loaded into the cartridge in the needle and resiliently straightened by at least the inner wall of the needle. In the out-of-phase mode, the most distal fastener near the distal opening of the cartridge is resiliently straightened only by the inner wall of the needle. The position of this fastener is called the deploy position, because the fastener is, in fact, ready for deployment. As the cartridge or needle rotates from the out-of phase to the in-phase mode, where the mechanical constraint is removed from the fastener in the deploy position, the resiliently straightened fastener resumes its original curved shape, protruding from the slits and gripping the surrounding tissue. Since the slits of both cartridge and needle are open distally, the deployed fastener is free to slide away from the delivery device when the fastener device is withdrawn from the tissue.
To prevent fastener migration with time, tissue ingrowth holes or grooves can be channeled into the fastener.
By indenting a portion of the slit opening of the needle, one can selectively deploy a portion of the fastener while the remaining portion of the fastener remains within the device. For example, the distal half of the slit is made slightly wider than the proximal half. When the needle and the cartridge slits are set nearly in-phase, or referred to hereinafter as semi-in-phase, the distal half of the fastener deploys into the surrounding tissue while the proximal half of the fastener remains within the device. A partially deployed fastener is called semi-deployed. The semi-deployed fastener is particularly helpful in endoscopic surgery. Using the gripping element on the deployed distal half, a surgeon is now capable of pulling, tightening and manipulating the tissue to be fastened for a superior and gap-free repair before fully deploying the entire fastener.
To prevent the semi-deployed fastener from slipping out during tissue manipulation, tapered fastener holding elements may be carved into or incorporated onto the inner wall of the needle. The holding elements provide anchoring for the portion of the fastener remaining in the needle. The tapering prevents jamming of the fastener during the transition between out-of-phase to in-phase.
Depending on the surgical needs, sometimes the proximal half of the fastener can provide better assistance in tissue manipulation than the distal half of the fastener. It is possible to open the slit in ways to allow the deployment of either the distal or the proximal portion of the fastener in the semi-in-phase mode. One side of the slit is indented at the distal half while the other side of the slit is indented at the proximal half. Depending on the direction of cartridge rotation, relative to the needle, the semi-in-phase mode can bring out either the distal or the proximal end of the fastener, with tapered fastener holding elements supporting both semi-deployments.
The outer needle may have penetration markers to indicate the depth of tissue penetration. Furthermore, the needle has one or more orientation lines. The line may run longitudinally from the slit through the length of the needle to indicate the deploy direction of the fastener, this orientation line is called the deploy line. In some surgical manipulations, the deploy line is mostly hidden by tissues. Another orientation line may also be marked longitudinally directly opposite the deploy line, perhaps in a different color, pattern or shade; and is called the back line. The back line indicates where the back of the fastener will face.
The fourth component of the invention is a handle attached to the needle. The needle handle is made strong enough to puncture soft bone and to rotate the needle. For surgical applications where both deploy line and back line are invisible by direct view or endoscope, the needle handle is fixed in a position relative to both lines to indicate the direction of fastener deployment.
The fifth component of the invention is a handle for the cartridge. The cartridge handle is attached to the cartridge and made sturdy enough to assist tissue puncturing, but the most important function is to rotate the cartridge inside the needle. Similarly, the cartridge handle is also fixed in a position relative to the slit of the cartridge to assist in establishing the direction of fastener deployment.
Multiple fasteners can be loaded into the cartridge. After the first fastener is deployed, a fastener advancing device pushes another fastener into the deploy position. For example, a simple plunger connected to a mechanical lever can be used to advance fasteners one after another into the deploy position.
To prevent accidental puncturing of the surgeon or unintended tissue of a patient by the sharp needle, a moveable sleeve may be extended to cover the needle. In addition to the protective purpose, the sleeve can also serve numerous functions to assist surgeries. After the needle is inserted into tissue, the sleeve can be used to push and position the punctured tissue into proper place for an optimal reattachment. To fasten a bulging or herniated disc, the sleeve may be used to push and hold in the bulging annulus during the deployment of fasteners.
The fastener delivery device utilizes the rotating cartridge, relative to the needle, to deploy fasteners into tissue through overlapping slits. Similar fasteners can be resiliently straightened in a needle without the cartridge, but with a plunger fitted inside the needle behind the fastener. After insertion of the needle into tissue, the plunger is held stationary while the needle is slowly retracted or withdrawn from tissue, thereby deploying the fastener out of the distal opening of the needle. In tissue, the fastener resumes the original resilient curvature and tightly fastens onto the tissue. Multiple fasteners can also be loaded into the needle and deployed one at a time into different locations.
The fasteners can be made with alloy, pure metal, polymer, ceramic or composites. The fasteners can also be formed from modular parts, coated with lubricants, drugs, growth factors, antibiotics, hydrophilic compounds, hydrophobic compounds, self-sealing materials, swellable components, plasma coating or other substances. The curvature of the fasteners can be made symmetrical, asymmetrical or with multiple curvatures. The fasteners or parts of the fasteners can be made with biodegradable materials or with permanent materials. The fasteners or parts of the fasteners can be attached with or attached to a suture or other fastening devices.
In preparation for use, the fastener delivery device is set in the out-of-phase mode with a fastener in the deploy position. The tissue needing to be fastened is chosen, prepared and arranged. The device is then guided to the proper depth and orientation by the penetration markers, orientation line(s), endoscope, X-ray, ultrasound, MRI and/or other technique.
Guided by an arthroscope and the penetration markers, the device punctures the meniscal body and traverses the tear. Through the indented slit of the needle, the distal half of the fastener with gripping element is deployed. The torn portion is gently pulled in and manipulated back to the main body of the meniscus, then the fastener is fully deployed by setting the cartridge fully in-phase to close the tear. The device is now ready to be withdrawn, or another fastener may be deployed through the same puncture site in a different direction to ensure a tight closure.
To deploy another fastener, the cartridge is reset from the in-phase back to the out-of-phase position. Another fastener is advanced in the cartridge chamber to the deploy position. The needle handle may then be used to rotate the device, for example, by 180xc2x0 for the deployment of another fastener. If two fasteners in the puncture site are sufficient to hold the tear at the location, the device is ready to be withdrawn from the meniscus. To prevent accidental scraping of the delicate articular cartilage in the knee joint, the sleeve may be slid over the sharp needle before resetting the device to the out-of-phase position in preparation for deployment of an additional fastener or prior to withdrawal of the device.
For simplicity in the remaining method summary, operative procedures of the device, such as out-of-phase, in-phase, fastener advancement, sleeve sliding, device rotation, puncture or withdrawal will not be mentioned in great detail, unless the operation is greatly varied from that described above.
To fortify the longitudinally oriented collagen fibers in a torn anterior cruciate ligament, ACL, some specially designed fasteners are deployed to grip and bundle the collagen fibers of the ACL together like a collar. Frequently, the ACL is stretched and irreversibly lengthened prior to breaking. Therefore, the collar may not always be placed near the end of the tear. The placement of the collar is determined after manipulating and fitting the torn ACL in the patient""s leg to ensure appropriate length after reattachment.
A ligament holding device may also be included to hold the ACL stationary and to guide insertion of the fastener delivery device containing the collar fasteners.
For ACL tears close to the tibia or femur, a trocar is passed through the collar to the bone to establish an ACL reattachment position. A cannula is inserted as a sleeve over the trocar and contacts the bone. The trocar is then removed and replaced with a drill having drill stops to prevent excessive penetration into the bone. After drilling, the drill is removed and replaced with the fastener delivery device into the drilled hole through the cannula. Unlike the collar fasteners mentioned earlier, the gripping elements for the bone attachment are designed to resist vertical or longitudinal pull out. The length of the fasteners is sufficient to span the depth of the drilled hole to beyond the collar in the torn ACL. Prior to deployment of the fasteners, the cannula is lifted beyond the slit of the needle. The collagen fibers of the ACL are in contact with the delivery device, especially with the slit portion of the needle. The first fastener is then deployed. The gripping elements on one end of the fastener anchor onto the collar-fortified ACL fibers or may even latch onto the collar itself. The gripping elements on the other end of the fastener anchor into the hole in the bone. Due to the spring-like property built into the fastener body, the gripping elements at both ends are constantly compressing the tissues, in this case the ACL fibers and bone, making the fastening strength exceptionally strong. To ensure adequately strong reattachment, multiple fasteners, preferably deployed in different directions, can be loaded into the same drilled hole without lifting the fastener delivery device.
Often, the ACL is torn at or near its mid-section. A similar technique using the ligament holder and collar fasteners is used to install two sets of collars, one on each torn end of the ACL. The fastener delivery device is threaded through the collars. The fastener delivery device is loaded with fasteners similar to the ones used to attach the ACL to bone. With the indented slit on the needle, partial deployment of the first fastener is helpful to pull and manipulate the distal ACL fragment into place. Sliding the sleeve over the needle can also be used to push tissue, in this case the proximal ACL fragment, to tightly rejoin the distal ACL fragment. The fastener is then fully deployed, gripping both fragments of ACL fibers fortified by two sets of collars.
The fastener delivery device of the present invention can be used through a small opening to reattach a tendon back to the bone without sewing, manipulating or tying sutures. Similar to reattaching the ACL to bone, a trocar is used to pierce and guide the tendon into the proper position, where a hole will be drilled in the bone. A cannula is inserted over the trocar, and then the trocar is replaced with a drill creating a hole in the bone. The drill is then replaced by the fastener device inserted through the tendon into the bottom of the bone hole. The cannula is lifted so that the slit opening of the device is in contact with tendon tissue. If necessary, the tendon can be pushed and positioned by the sliding sleeve. The fasteners in the device should have sufficient length to grip both the bone and the tendon tissue. With time, similar to the reattached ligament, the tendon can and most likely will permanently reattach back onto the bone.
For soft bone, such as the humeral head in the shoulder, the needle of the device could possibly pierce a tendon to be reattached and puncture into the humerus without using the trocar, cannula and drill. The sleeve of the device may be used to manipulate the tendon for a tight and permanent repair.
To fasten bulging or herniated discs, the spring-like fasteners mentioned in the invention are made extra long with multiple gripping elements. For the best result, the needle of the fastener delivery device punctures the bulging portion and is guided into the disc by anteroposterior and lateral fluoroscopy or other technique. In cases where the bulging portion of the disc is well concealed by the lamina of the vertebra, a small amount of the bone can be removed to allow penetration of the delivery device. When the appropriate depth is reached, the sliding sleeve is used to push and hold the bulging portion of the disc inward; the fastener is deployed to grip and compress the previously bulging tissue back in place. To make possible the push and hold technique using the sleeve during deployment of the fastener, the distal opening of the sleeve also contains a slit, which may be oriented to overlap the slit of the needle. As the device is set in the in-phase position, the slits of the cartridge, needle and sleeve are aligned, allowing the fastener to deploy and hold the compressed tissue in place. Similar to previously mentioned surgical procedures, more than one fastener can be deployed through the puncture site, preferably toward different directions, to enhance a permanent fastening. The spring-like fasteners with multiple gripping elements provide an exceptionally strong holding strength with constant fastening forces holding back the repaired annulus, away from nerves.
The fastener directly, actively and elastically holds the bulging or herniated tissue back without removing the nucleus pulposus. Therefore the bulging or herniated disc may be repaired without loss of nucleus pulposus.
Some surgeons may like to approach the disc repair anteriorly. After retracting the abdominal contents, the device can be guided, perhaps by fluoroscope or other means, through the disc to the bulging or herniated portion. As the tip of the device reaches or nears the bulging surface, the distal half of the fastener is deployed. The bulging portion of the disc is gripped and pulled inward, then the fastener is totally deployed to fasten the bulged disc.
To prevent possible leakage of the nucleus pulposus around the fastener, prior to device insertion into the disc, a sealing patch, made with elastic and biocompatible material with closure capability, is inserted on the needle against the distal opening of the sleeve. For best results, the sleeve is fixed proximally and stationary to provide a position where the proximal tip of the soon to be deployed fastener will grip the sealing patch. Using similar guiding, inserting and compressing techniques, the sealing patch is tightly compressed, adhered or maybe even embedded into the previously bulging or herniated annulus. As the fastener is deployed, it grips the patch to seal possible leakage of nucleus pulposus. The sealing patch is a preventive measure and is optional.
Other fastening devices can be used to fasten the bulging or herniated annulus. A simple screw with tissue holding threads can be inserted through a pre-punctured hole, to compress and hold the bulging or herniated disc away from the encroached nerve. The screw can be made with a locking device to prevent loosening and/or with threads having a variable pitch to compress bulging or herniated tissue. Depending on the severity of the bulge or herniation, a simple staple or tack with tissue holding elements may be sufficient to fasten the weak annulus.
Suturing can also be used to fasten bulging or herniated discs. For example, the midsection of a small dumbbell-shaped rod is tied to a suture. The rod with suture is fitted inside a needle. Behind the rod, a plunger is inserted into the needle. The needle is guided through the bulging or herniated disc. With the plunger, the rod is pushed out of the distal opening of the needle, outside the annulus. The rod is now caught by the outer surface of the annulus and acts as an anchoring device for the suture. The needle is removed. A washer is threaded with the suture, slipped down to the bulging disc, compressed and tied. For surgical convenience, the washer can be made in conjunction with a suture-locking device to eliminate suture tying. The suture may be made of natural or synthetic fibers, such as gut, polymers and metals.
For fastening bulging or herniated discs, other fastening devices, such as tacks, tissue anchors, staples or clamps, can also be used. To prevent possible leakage of nucleus pulposus, a sealing patch can be used in conjunction with any of the fastening devices mentioned.
For urinary and fecal incontinence, the spring-like fasteners of the present invention can be guided into the body and deployed to grip and elastically close the leakage of the sphincters. For insertion of the fastener delivery device, numerous existing guiding techniques, such as cystoscope, ultrasound, anteroposterior-lateral fluoroscopy, MRI or others, can be used effectively and accurately to guide the insertion and deployment of the fasteners. Again, multiple fasteners can be used to ensure proper closure of the sphincter.
To provide instant feedback to the surgeon, a pressure sensing catheter balloon, strain gauge, or tightening detecting instrument can be inserted into the leaking portion of the rectum and/or urethra As the fastener deploys and tightens the leaking portion, the instrument can provide instant information to the surgeon regarding the placement and effectiveness of the deployed fastener. For fluoroscopic image enhancement, the catheter or instrument can be made or coated with radiopaque material to perfect the accuracy of the fastener delivery device insertion. For ultrasound image enhancement, echogenic enhancing material can be used.
Especially among elderly patients, the elasticity of sphincters varies greatly. Elasticity sensing balloons or instruments are particularly helpful in determining the elasticity of the sphincter tissues so that surgeon can select fasteners with appropriate closure strength and curvatures for optimum repairs.
Utilizing the elastic curvature of the fastener and the pliable nature of the flexor retinaculum, the fastener delivery device is inserted into the flexor retinaculum, perpendicular to and over the median nerve. As the fastener is deployed toward the palm inside the retinaculum, the curvature of the fastener forms the shape of an arch, lifting the flexor tissue, which was compressing the median nerve. With several other fasteners deployed side by side, a tunnel is created to relieve median nerve compression without cutting the flexor retinaculum. The fasteners can even be made with biodegradable materials, which degrade with time after relieving the pain.
Adding to the versatility of the fastener delivery device, the slit can be double indented for semi-deploying either the proximal or distal portion of the fastener, depending on the direction of cartridge rotation. This feature is particularly helpful when alternating between fasteners to create interlocking tissue fastening. To enhance the double indented feature of the needle slit, the curvature of the fasteners can be made asymmetrical. For example, the first fastener in the deploy position is made with a curvature near the proximal end of the fastener. The following fastener in the cartridge is made with a curvature near the distal end of the fastener. After semi-deploying the proximal half of the first fastener, the tissue is tightened by pushing, then fully deploying the first fastener. The device is slightly withdrawn and reset to out-of-phase. The following fastener is advanced into the deploy position. The distal portion of the second fastener is semi-deployed into the tissue. For the second fastener, the tissue is tightened by pulling the device before full deployment. With tissue tightening by pushing and pulling, the fasteners interlock the tissue, through one needle puncture. In addition to pushing and pulling on the semi-deployed fasteners, twisting provides yet another dimension and benefit to the tissue manipulation and inter-locking fastening.
With an angiogram, the location of arteries supplying a tumor is mapped out. The fastener delivery device is inserted and guided to a tumor-feeding artery. With the needle slit facing the artery, the proximal portion of the fastener is deployed under the artery. The device may then be gently pushed to compress and restrict the artery. While pushing, the fastener is fully deployed to clamp and restrict the artery. If necessary, the device is slightly withdrawn, reset and another fastener is advanced from the cartridge. The second fastener is semi-distally deployed over the artery. The device may then be gently pulled to hook and further restrict the artery. While pulling, the second fastener is fully deployed to shut the blood flow. More fasteners can be deployed to ensure a complete closure of the artery feeding the tumor.
The needle of the device may be curved with a flexible cartridge to accommodate rotation within the curved needle to reach under skin or around organs and tissue into a target site.
Many other surgical procedures can utilize the fastener and the delivery device. Some examples follow. The fastener and delivery device can endoscopically attach dislocated organs. For weight loss purposes, fasteners can be used to slow stomach emptying by restricting the pyloric sphincter or pyloric canal. The fasteners can also be used to attach medical devices inside the body.
The fastener and the delivery device can serve in numerous endoscopic procedures, which require connecting, reattaching, holding, fortifying, restricting, closing, compressing or decompressing tissues or other devices.
In brief summary, some of the possible benefits of the sustained gripping fasteners and the delivery device follow: (1) grip tissue continuously, (2) minimize fastener migration, (3) minimally invasive, (4) deploy multiple fasteners within a puncture site, (5) access deep body targets, (6) support and fortify fragile tissue, (7) reattach tissue without suture, (8) attach tissue to bone, (9) require minimal surgical space, (10) attach to other fastening devices, (11) versatile, (12) provide permanent and/or degradable fastening, (13) simple to use, (14) manipulate tissue, (15) restrict or close orifices or vessels, (16) compress or decompress tissue, and (17) provide directional fastening.